Compared to Python or Ruby, NodeJS has phenomenal performance. The single threaded argument is also flat out wrong, given that you have clustering or web workers to take advantage of every core. It's also completely misleading even within a single core, as non-blocking nature of JS will accomplish on a single core what otherwise behaves as threading would.

the cool years of node are just beginning with AWS Lambda and other cloud services that help node.js scale easier

Wait, maybe I am dumb, but why do you need AWS Lambda to scale Node.js better? You use something like Lambda which is build to handle one request per instance to scale something which is single threaded anyway?

Say I have an endpoint that has to parse a giant JSON object, which can take 100ms to parse... if that locks the thread it can block another request. With lambda I would just make one lambda function for each route and routes won't block each other.